Method for the manufacturing of a mould body and a mould body manufactured according to the method

ABSTRACT

The invention relates to a method for manufacturing a mould body ( 40 ) serving as an original or master or, alternatively, a matrix, said mould body having at least one surface area ( 41   a ) in the form of a microstructure, designed so that it can be transferred as a complementary surface area to a matrix or an object. The mould body ( 40 ) is constructed from one or more prefabricated discrete elements ( 41 ). A base plate belonging to the mould body ( 40 ) is applied and secured in at least one of these discrete elements ( 41 ). This element shall be provided with said surface area ( 41   a ) in the form of a microstructure. A matrix or object formed by the mould body ( 40 ) is provided with a complementary microstructured surface area from said discrete elements. 
     The invention also relates to a mould body produced in this way.

TECHNICAL FIELD

The present invention relates primarily to a method for manufacturing amould body serving as an original or master or, alternatively, a matrix.

Mould bodies of this type are used preferably in the manufacture ofvarious plastic objects wherein the manufacture may primarily bepermitted to occur in die-casting, hob-moulding or injection-mouldingequipment.

An original or master must be used to enable the manufacture and shapingof a matrix.

A matrix is used to enable the manufacture and shaping of one or moreobjects wherein a (negative) surface structure of the matrix will bereproduced against the object as a (positive) complementary surfacestructure.

More specifically the present invention relates to a method formanufacturing a mould body having at least one,surface area in the formof a microstructure. This surface area shall be so designed that it canbe transferred as a complementary surface area to a matrix or,alternatively, an object.

The invention relates secondarily to a mould body, or a mould bodyarrangement, that can be manufactured by means of the method with atleast one chosen surface area formed as a microstructure, designed sothat it can be transferred as a complementary surface area to a matrixor, alternatively, to an object.

The method and the mould body produced thereby may be used in themanufacture of an origin al or a master and also in the manufacture ofmatrices. For the sake of simplicity substantially only the former willbe described in the following.

When the mould body in accordance with the invention is used as anoriginal or a master, a surface area of the mould body with a positivemicrostructure will form a complementary surface area of the matrix witha negative structure, against which the microstructured object cansubsequently be formed having a complementary surface area of the objectwith a positive microstructure.

The terms positive and negative surface structure should be understoodin the first place to mean surfaces having irregular microstructuresbut, in the second place, also plane surfaces.

If the mould body is used for manufacturing a matrix having a surfacearea with a negative microstructure, objects manufactured via the matrixwill have a surface area with a positive microstructure having a patterncomplementary to the pattern of the matrix.

A matrix consists of a unit or an arrangement of units designed for usein mould parts for die-casting, hob-moulding and/or injection mouldingor equivalent procedure.

BACKGROUND ART

Machines for manufacturing objects in the form of plastic components andthe like, based on die-casting, hob-moulding and/or injection mouldingor equivalent procedures are already known in various forms.

In the case of die-casting a hot (approx. 400° C.) liquid plasticcompound is pressed under high pressure into a cavity defined by mouldparts placed together, the plastic compound being allowed to cool tosolid form before the mould parts are opened.

Die-casting also includes the insertion of a plastic compound betweenthe mould parts, the plastic compound being caused to cure and solidifyby its constituents.

In the case of hob-moulding a solid plastic component is embossed by thestructure of the matrix.

In the case of injection moulding the plastic compound is permitted topass through a nozzle, the peripheral shape of which is reproduced asthe cross section of a bar, rod or ribbon.

With machines for die-casting it is known for only one or both mouldparts to be provided with one or more matrices and to allow the hotliquid plastic compound to solidify (at approx. 140° C.) between theclamped mould parts before they are opened and the solidified componentcan be pushed out.

Machines with said mould parts thus comprise one or more matrices withone or more negative surface structures, in order to be able toreproduce the negative surface structure against the plastic componentor object as a positive surface structure.

When reproducing a microstructure belonging to the matrix on a plasticcomponent or object manufactured in a machine it is known to first havean original or master manufactured in suitable manner and thenmanufacture a matrix belonging to and adapted for the machine, from thismaster.

Although the present invention may be used as an arrangement in amachine for manufacturing objects of substantially optional form, in theform of plastic components, for the sake of simplicity and by way ofexample, the following description will deal with the manufacture ofplastic components having a single surface section provided with apositive microstructure.

A previously known method for having a master or matrix manufactured isto apply and secure a number of units and/or discrete elements on a baseplate, forming a desired positive or negative surface structure.

Another previously known method for having a master manufactured is toutilise lithographic methods, in which case it is advantageous to makeuse of lithographic methods that have been developed primarily withinthe microelectric field.

A previously known method for the manufacture of an original or master,the manufacture of a matrix and the manufacture of an object, will bedescribed in more detail in the following, with reference to FIGS. 1-3.

It is also known that, when die-casting or hob-moulding plasticcomponents in a machine wherein one or more surface portions of theplastic component shall have a microstructure, mould parts pertaining tothe machine using one or more matrices pertaining to the mould parts,must be made from a stable material that will withstand the highpressures prevailing during the manufacturing process and will notbecome worn unnecessarily quickly by the thermal and mechanical wear towhich the mould parts and matrices are subjected during the actualcasting process.

The method shown in FIGS. 1-3 is intended to illustrate the “LiGAmethod” which is designed to enable the creation of a deeplithograph-related structure with the aid of X-rays, with galvanoplatingfor plastic casting or embossing.

The known LiGA technology is capable of giving an edge area a shape in atwo-dimensional plane corresponding to a silhouette, where the thicknessor depth chosen provides the three-dimensional height or structure. Inthe following this structure is termed a 2D-structure.

The object of the invention is, when necessary, to give the edge area athree-dimensional surface structure, such as a high-rise area, and thiswill be termed a 3D-structure in the following.

DISCLOSURE OF THE INVENTION Technical Problems

Taking into consideration the fact that the technical deliberations aperson skilled in the relevant art must perform in order to offer asolution to one or more technical problems posed, constitute initiallyan insight into the measures and/or sequence of measures to be taken,and also a selection of the means required, and as a result thereof thefollowing technical problems are probably relevant to the development ofthe present invention.

Taking into consideration the background art as described above and aswill be explained more fully with reference to the following descriptionof the method illustrated in FIGS. 1-3, it should appear as a technicalproblem to be able to conceive a method for having a mould bodymanufactured that serves as an original or master or, alternatively as amatrix, said mould body having at least one surface area formed to amicrostructure, wherein this surface area of the mould body is designedto be transferred as a complementary surface area to a matrix or anobject, and also a mould body therefor wherein the method andmanufacturing procedure is considerably simpler, quicker and/or lessexpensive than the method shown to be previously known through the LiGAtechnology.

It is a technical problem to be able, using simple measures, to createsuch criteria that an object produced, without considerable expense, canshow a deep lithograph-related structure, without the need to use X-raysor the like that demand high energy levels.

It is also a technical problem to be able, using simple measures, tocreate a microstructured edge surface having a width or depth far inexcess of a depth obtained by means of the LiGA technology.

It is furthermore a technical problem to be able, using simple measures,to create a microstructured edge surface where the microstructure maydeviate from a diffractive structure and/or a plane structure offered bythe LiGA technology, such as ridges and grooves oriented at a differentangle to the ridges and grooves that can be produced using the LiGAtechnology.

It is a particular technical problem to be able, using simple measures,to create a surface area for the object, such as to and along the edgeof a cavity, that has an intact positive 3D-microstructure.

It is also a technical problem to be able to perceive the significanceof and advantages associated with having a number of discrete elementsprefabricated in one and the same manufacturing process, and to selectthe thickness of each discrete element by cutting a slice from amachined blank or, in the manufacturing process, machine the thicknessfor a plurality of such discrete elements.

A technical problem also lies in being able, using simple means andmeasures, to produce the mould body with the aid of a cut slice, thethickness of which is designed to create the depth dimension of a cavityand, with the positive microstructure of the object well adapted, to beable to cover the entire surface area corresponding to the chosen depthdimension.

A technical problem also lies in being able to perceive the technicaldesign measures required for the mould body in order to obtain anobject-related microstructured surface area capable of having a largerand more exactly shaped 3D surface structure than can be achieved usingthe previously known LiGA method.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with applying and securing at least oneprefabricated discrete element to the base plate of a mould body inorder to produce a cavity or elevation, such as a plateau, pertaining tothe object.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with allowing this element to beprovided with one or more of said surface areas formed to amicrostructure, by producing said surface areas by means of simple,known procedures.

It is furthermore a technical problem to be able to perceive theadvantages associated with allowing said surface area for the element,formed to a microstructure, be edge-oriented and/or surface-oriented.

Advantages are to be gained from being able to utilise one or morediscrete elements since selected surface areas can then easily be formedwhen the element is separated from the base plate, and can also beformed by means of simple, known measures, such as forming a 2Dstructure, a 3D structure and/or a surface co-ordination and/or surfaceseparation thereof.

A technical problem lies in being able to perceive the significance ofand the advantages associated with allowing a matrix or an objectproduced by such a mould body, to be provided with one or morecomplementarily shaped microstructured surface areas from said discreteelements firmly related to the base plate.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with allowing the surface area of thediscrete element formed to a microstructure to be designed with adistinct edge or rim extension fitting to the base plate.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with allowing the surface area formedto a microstructure to be chosen to have at least one surface area with2D structure designed for diffractive optical properties, preferablywall-related.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with allowing said surface area formedto a microstructure to be chosen to have at least one surface area with3D structure designed for sensor-active properties, preferablywall-related.

It is also a technical problem to be able to perceive the significanceof and the advantages associated with allowing each, or at least some ofsaid discrete elements to be chosen as a slice cut from a longitudinallyextending bar with a surface width or surface extension along the bar,having 2D structure and/or 3D structure, formed to a microstructure.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with allowing each of said discreteelements to be chosen as a part of or a slice cut from a solid ofrevolution with a surface width or surface extension along the solid ofrevolution formed to a microstructure.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with allowing said surface width with2D structure formed to a microstructure to be produced from said solidof revolution by means of turning with the aid of a diamond bit.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with allowing a lathe tool tip providedwith a diamond to be shaped so that, in combination with the feedingmovement of the lathe tool, it can produce one or more surface widthswith 2D structure surrounding the solid of revolution.

A technical problem also lies in being able, using simple measures, tocreate such criteria that the surface structure of the surface width caneasily be adjusted to reveal diffractive optical properties.

It constitutes a technical problem in being able, using simple measuresto create a number of identical discrete elements in one and the samemanufacturing process and, using a lathe tool, turn the thickness foreach discrete element inserted in a fixture belonging to the chuck.

Said surface width, such as the one with diffractive properties, shouldpreferably be capable of being delimited by parallel-related, or atleast substantially parallel-related, section surfaces for the solid ofrevolution in order to produce said discrete elements and with definededge-related surface areas.

A technical problem also lies in being able to specify a mould bodyarrangement with at least one surface area formed to a microstructureand where the surface area of the mould body is designed to betransferred to a matrix or, alternatively to an object, therebyindicating the possibility of building up the mould body and/or mouldbody arrangement from several, at least two, parts—a base plate and atleast one prefabricated discrete element—where also a base plate can beapplied and/or secured in at least one such discrete element, where atleast said element shall be provided with at least one surface area inthe form of a 2D microstructure.

A technical problem also lies in being able, with a mould body of thekind described in the introduction, to allow said element to be providedwith at least one complete surface area in the form of a microstructurewhen the element is applied on the base plate.

A technical problem also lies in being able, using simple means, tocreate such criteria that the surface area pertaining to said discreteelement and in the form of a microstructure can be adapted to fitdirectly onto an upper surface of the base plate by means of a distinctedge or rim extension.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with, in a simple manner, allowing saidsurface area formed to a microstructure to be provided with at least onesurface area designed for diffractive optical properties and where saidsurface area can be wall-related to said discrete elements.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with said surface area formed to amicrostructure being provided with a surface area with 2D and/or 3Dstructure, designed for sensor-active or other properties, where saidsurface area preferably can be wall-related to said discrete elements.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with allowing said discrete elements toconsist of a thin slice from a longitudinally extending bar having asurface width formed to a microstructure along the bar.

A technical problem also lies in being able to perceive the significanceof allowing said discrete element to consist of a thin slice from asolid of revolution having a surface width formed to a microstructureoriented about the solid of revolution.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with allowing at least the surface areaof the base plate facing the discrete element to be provided with awear-and-release layer designed for manufacturing a matrix or an object.

A technical problem also lies in being able to perceive the significanceof and the advantages associated with allowing at least the surface areaof said elements formed to a microstructure to be provided with awear-and-release layer designed for the manufacture of a matrix or anobject.

Solution

For solving one or more of the above technical problems the presentinvention proposes a method for manufacturing a mould body serving as anoriginal or master or, alternatively, as a matrix, said mould bodyhaving at least one surface area in the form of a microstructure,designed so that it can be transferred to a matrix or an object, thelatter via plastic moulding, plastic embossing and/or injectionmoulding. In such a method, the invention particularly states that abase plate be applied and secured in at least one prefabricated discreteelement.

This element shall be provided with said surface area with 2D and/or 3Dstructure, in the form of a microstructure, and a matrix or objectformed by the mould body shall be provided with a complementarymicrostructured surface area from said discrete element.

As preferred embodiments falling within the scope of the inventiveconcept it is stated that the surface area belonging to the discreteelement and formed to a microstructure shall be adapted to fit onto thebase plate by means of a distinct edge or rim extension.

It is also stated that a surface area in the form of a 2D structuredmicrostructure shall be chosen to reveal a surface area for diffractiveoptical properties, preferably wall-related.

It is furthermore proposed that a surface area in the form of a3D-structured microstructure shall be chosen to reveal at least onesurface area designed for is sensor-active properties, preferablywall-related.

The invention particularly states that said discrete element may bechosen as a slice cut from a longitudinally extending bar with a surfacewidth or surface extension along the bar formed to a microstructure or,alternatively, said discrete element may be chosen as a part of, or aslice cut from a solid of revolution having a surface width about thesolid of revolution formed to a microstructure.

In the latter application it is proposed according to the invention thatsaid surface extension in the form of a microstructure is produced bymeans of turning in a lathe with diamond bit.

It is here specified that a lathe tool tip of diamond material, suitablefor turning, shall be shaped so that, in combination with the feedingmovement of the lathe tool, it can produce one or more surfaceextensions on the solid of revolution.

It is in particular proposed that the surface structure of a surfaceextension shall be designed to reveal diffractive optical properties.

If said discrete element is chosen as a part or a slice cut from a solidof revolution, it is stated that said surface area for the discreteelement shall be defined by parallel-related or substantiallyparallel-related section surfaces for the solid of revolution.

The present invention also relates to a mould body having at least onesurface area in the form of a microstructure, where the surface area,etc. of the mould body is designed so that it can be transferred as acomplementary surface area to a matrix or, alternatively, to an object.

In such a mould body it is stated that at least one prefabricateddiscrete element is applied and/or secured to a base plate, and thatsaid element is provided with said surface area in the form of amicrostructure.

As preferred embodiments falling within the scope of the inventiveconcept it is stated that said element shall be provided with a completesurface area in the form of a microstructure when the element is appliedon the base plate.

It is also stated that the surface area pertaining to said discreteelement and in the form of a microstructure is adapted to fit directlyonto an upper surface of the base plate by means of a distinct edge orrim extension.

It is also stated that said surface area formed to a microstructureshall be provided with a surface area designed for diffractive opticalproperties.

The opportunity is particularly offered of allowing said surface area tobe wall-related to said discrete element.

Said surface area formed to a microstructure is provided with a surfacearea designed for sensor-active properties.

Said surface area shall also preferably be wall-related to said discreteelement.

The invention particularly recommends that said discrete element shallconsist of a dimensioned thin slice from a longitudinally extending barhaving a surface width and surface extension along the bar, formed to amicrostructure.

Said discrete element consists of a thin slice from a solid ofrevolution.

The invention is also based on at least the surface area of the baseplate facing the discrete element being provided with a layer designedfor the manufacture of a matrix or an object.

Over and above it is stated that at least the surface area of saidelements formed to a microstructure shall be provided with a layerdesigned for the manufacture of a matrix or, alternatively, an object.

Advantages

The advantages that can be considered most significant for a method formanufacturing a mould body serving as an original or master or,alternatively, as a matrix, and a mould body that can be manufactured inaccordance with the method are thus that criteria have been created,using simple measures and means, to enable desired mould bodies to becombined by combining a number of prefabricated discrete elements formedto a microstructure, and applying or securing these to a base plate.

The opportunity is thus offered of forming and machining theprefabricated discrete element in order to produce a surface area orareas, formed to a microstructure, and to choose the wall thickness ofthe discrete element corresponding to the depth of a cavity or theheight of an elevation formed by the element in a matrix or object.

The invention also offers the opportunity of allowing the surface areapertaining to the discrete element, and formed to a microstructure, tobe designed having a distinct edge extension to fit the base plate.

The features that can primarily be considered characteristic of a methodfor manufacturing a mould body serving as an original or master or,alternatively, as a matrix, said mould body having at least one surfacearea formed to a microstructure, are defined in the characterizing partof the appended claim 1 and the features that can primarily beconsidered characteristic of a mould body having at least one surfacearea formed as a microstructure, are defined in the characterizing partof the appended claim 12.

BRIEF DESCRIPTION OF THE DRAWINGS

A currently proposed embodiment of a known, method for manufacturing acomplete mould body serving as an original or a master, and a method forthe same purpose but specifying the properties significant to thepresent invention, as well as a mould body manufactured in accordancewith the principles of the invention, will now be described more fullywith reference to the accompanying drawings in which;

FIGS. 1A-D show in a sequence A-D, a previously known method formanufacturing a complete mould body to form an original or a master,

FIG. 2 shows how a matrix can be produced with the aid of this mouldbody and

FIG. 3 shows how, with the aid of said matrix, an object having a cavitycan be produced, the narrow wall section of the cavity having beenprovided with a 2D structure surface area formed to a microstructure,

FIG. 3A is an enlargement of a fragment of FIG. 3,

FIG. 4 shows in perspective a method according to the invention formanufacturing a mould body serving as an original or master or,alternatively, a matrix, with one or more discrete elements applied on abase plate,

FIG. 5 shows in perspective a longitudinally extending bar, where anumber of discrete elements, suitable for the mould body, can be chosenas slices cut from said longitudinally extending bar, with a surfacewidth along the bar formed to a microstructure,

FIG. 6 shows in perspective a cut slice with only a part of the edgesection showing a microstructure,

FIG. 7 shows in perspective a solid of revolution illustrated as atoroid,

FIG. 8 shows in perspective an embodiment in which said discreteelements can be chosen as a part or a slice cut from a solid ofrevolution with a surface width formed to a micro structure about thesolid of revolution,

FIG. 9 shows an application in which a light source emitting severalwave lengths illuminates a diffractive plane surface to enable lightintensities separated into different wave lengths to be sensed indifferent receivers,

FIG. 10 shows the construction of a mould body in accordance with FIG.9, from a number of discrete elements, to produce an object with aplateau as a matrix, and

FIG. 11 shows a view from above of a chuck in a lathe, where a fixturesupports a number of individual discrete raw material pieces which,after turning and possibly further machining, can form discreteelements.

DESCRIPTION OF A PREVIOUSLY KNOWN METHOD FOR MANUFACTURING A MOULD BODY

In FIG. 1 the positions of FIGS. 1A, B, C and D show a sequential courseof events for manufacturing a mould body 10 serving as an original ormaster or, alternatively, as a matrix, said mould body having at leastone (positive) surface area 2 a′ formed to a 2D microstructure anddesigned to be transferred to a matrix as a complementary surface area21 a having 2D structure.

Position A illustrates a substrate 1, such as titanium, coated with aplastic material 2, degradable by X-rays, in the form of a layer with atypical thickness of about 3 mm or less.

Position B illustrates that a lithographic mask 34 is applied above thislayer, the mask having one or more discrete sections, such as thesection 3 of gold, applied to a film 4 such as a hapton film.

The layer 2 is now illuminated with the aid of parallel X-rays 5,through the mask 34, and the X-rays are prevented from passing throughthe discrete section 3 and form an unaffected layer area. 2 a in thelayer 2 below.

The X-rays 5 pass through the film 4 in the surface areas of the layer 2that are not shadowed by the discrete layer 3, and degrade the layersection 2 b.

The maximum thickness (t) of the layer 2 is dependent on the energysupplied by the X-rays 5 and the thickness is thus in practice limitedto less than 2 mm, perhaps 3 mm exceptionally.

In a process step not shown, the degraded layer sections 2 b are removedand only a number of layer areas that have not been affected, like thearea 2 a, remain on the substrate 1.

To further illustrate the known technology, the discrete section 3 showsa defining rim surface 3a having a 2D microstructure designed to be ableto offer diffractive optical properties in the embodiment shown.

The rim surface 3 a will now be transferred to the layer 2 as asilhouette with the-aid of the X-rays 5, and therefore forms a rimsurface 2 a′ with a 2D surface structure.

The surface structure of this rim surface will now be identical forevery plane oriented perpendicular to the X-rays 5.

It should be noted here that the rim surface 2 a′ can only consist of aplane surface or a number of parallel-related grooves and ridgesoriented in the direction of the X-rays, and after a known surfacetreatment it will form a surface with diffractive optical properties.

Position C illustrates that a layer 6, such as in the form of nickel, isapplied to the substrate 1 and over the section 2 a through a knownplating procedure.

Position C also illustrates how another layer 7, such as a layer ofcopper, is applied on top of the nickel layer 6.

The upper surface 7 a is thereafter made level and plane for the copperlayer and the titanium material of the substrate 1 is removed by meansof etching by known means, and the layer area 2 a is removed to form acavity 20 in the nickel layer 6.

It is thus shown in position D that an original or a master 10 ismanufactured having a recess or cavity 20 with an edge area having a2D-microstructured surface as a rim surface 2 a′.

It is obvious that instead of having a recess 20, the original may beshaped with a protruding plateau, a ridge 20 a, 20 b or the like.

From the original or master 10 manufactured here, position D in FIG. 1,a matrix 20 can be produced by means of plastic moulding or a similarprocedure.

Such a matrix 20′ is shown in perspective in FIG. 2 where a plateau part21 corresponding to the cavity 20 is integrated with a base plate 22 andwhere a chosen surface area 21 a, a rim area, is produced as acomplementary surface to the rim or surface area 2 a′.

Significant for this LiGA technology is that if a single master is to beprovided with a number of cavities, such as the cavity 20, these must beformed as laterally oriented cavities (not shown in FIG. 1), i.e.oriented in rows and columns, in the master 10.

FIG. 2 illustrates that the master 10 has been formed with a number ofcavities oriented in rows and columns and a number of plateau parts inwhich the cavity 20 forms the plateau part 21, have been produced inrows and columns.

There is nothing to prevent a microstructure being created through thisLiGA technology showing a surface area on the upper surface 21 b of theplateau part 21 and/or on edge areas other than the edge area 21 a shownin the drawing.

It is clear from FIG. 2 that the negative surface structure 21 a (andsimilarly the positive surface structure 2 a′) can be given a variationin the y-z-plane depending on the shape of the edge 3 a and thesilhouette or silhouette edge produced thereby.

Variation in the x-y-plane is only possible with a chosen variation inthe thickness -k- and thus in the thickness of layer 2.

The surface 21 a is thus deemed to have two-dimensional surfacestructure, 2D-structure.

FIG. 3 shows how a matrix 20′, according to FIG. 2, is used to form anobject 30 in the form of a number of cavities opening downwardly in aplastic component. One of the cavities has been designated 31 and thiscavity has a surface area 31 a with 2D structure formed to amicrostructure, that constitutes a complementary, positive surface areato the surface area 21 a.

This known LiGA technology offers a method which is limited in that themaximum depth (in x-direction) of a cavity is determined by the abilityof the X-rays 5 to degrade the plastic material 2 while, at the sametime, the microstructure 2 a′ of the edge areas is limited to being ableto correspond only to a silhouette of a surface 3 a.

Description of Embodiment now Proposed

A method in accordance with the invention will now be described morefully with reference to FIG. 4, for manufacturing a mould body 40serving as an original or master or, alternatively, as a matrix.

The following description assumes that FIG. 4 shows the construction ofa matrix and a comparison can therefore be made with FIG. 2, entirelyignoring the production according to FIGS. 1 to 3.

This mould body 40 is to be manufactured by allowing one or moreprefabricated discrete elements 41 to be applied on a base plate 42.

The prefabricated discrete elements may be shaped differently or thesame and are to be combined here to form a plateau (or cavity) on thebase plate 42 with a form complementary to the desired form of a plasticobject moulded against it.

For the sake of simplicity, FIG. 4 aims only to show in more detail thata discrete element 41 in the form of a right-angled prism is secured toa base plate 42.

The complete prefabricated discrete element 41 is also shown in FIG. 4in an upper position 41′, indicated in broken lines, a position it willassume before it is secured to the base plate 42.

The object of the invention is to manufacture a number of discreteelements, preferably identical, in a single manufacturing or machiningprocess, or at least in only a few manufacturing or machining processes.

These can then be manufactured integrating with each other asillustrated in FIGS. 5, 7 and 8, and where an element can be formed froma slice cut from a bar or a toroid.

These can also be manufactured by means of a manufacturing or machiningprocess in which a plurality of individual elements in the form of rawmaterials are machined simultaneously in a lathe, for instance,according to FIG. 11.

As previously shown with the known technology, this mould body 40 shallbe provided with at least one surface area 41 a in the form of amicrostructure so that it can be transferred to an object as acomplementary surface area.

If the surface 41 a is chosen with a 2D structure as in FIG. 2, objects30 can be manufactured using a single matrix.

If the surface area 41 a is to have a different 2D structure, or 3Dstructure, the matrix must be made in two or three parts, in a mannerknown per se.

For the sake of simplicity FIG. 4 can be compared with FIG. 2, but withthe difference that according to the present invention an initialseparation of a discrete element 41 and base plate 42 is required sothat the microstructured surface portions of the discrete element 41 canbe formed by suitable methods and means without regard to the base plate42.

In the procedure or method according to the invention the mould body 40shall consist of several parts. This is illustrated in FIG. 4, in asimplified manner, as a base or bottom plate 42 with a discrete element41 secured thereto, where these parts can be combined to form a mouldbody unit.

The base plate 42 shall thus consist of a unit and be manufactured inone or more parts.

The base plate 42 should be sturdily dimensioned or well supported inorder to absorb the compressive forces occurring when the mould body isused as a matrix.

It is also proposed that the upper surface area 42′ of the plate 42 isprovided with a layer 42 b with high wear resistance and the ability toabsorb mechanical thermal stresses.

The plate 42 may thus be manufactured in a material and with a layer 42b that need not be coordinated with the material and the layers for thediscrete element 41.

The used discrete element or elements such as the element 41 may also bemanufactured in one or several parts.

The element 41 shall be dimensioned so that, together with the baseplate 42, it can absorb the compressive forces occurring in a machinewhen the mould body is used as a matrix.

It is also proposed that the microstructured surface area 41 a beprovided with a layer 41 b that has high wear resistance and the abilityto absorb mechanical thermal stresses.

The discrete element 41 may thus be manufactured in a material and witha layer 41 b that, at least over the microstructured surface area 41 a,need not be coordinated with the material and the layer 42 b in the baseplate 42.

FIG. 4 thus illustrates that one or more discrete elements 41 shall beapplied against a base plate 42 pertaining to the mould body 40, andsecured to an adapted surface portion 42 a oriented along the uppersurface area 42′ of the base plate.

FIG. 4 shows that a complete discrete element 41′ is placed somewhatabove the upper surface 42′ of the base plate 42 and that it shall belowered towards the surface portion 42 a and secured to the bottom plate42. The latter position is indicated with unbroken lines in FIG. 4.

In the embodiment described here the plastic moulded object will, as inFIG. 3, have a cavity with a shape fitting the complementary shape ofthe element 41.

In practical application the shape of the element may vary and deviateconsiderably from that shown schematically here.

The element 41 shall now have an edge-related surface area 41 a formedto a microstructure, but in which the form and structure of the surfacearea 41 a have been produced in a separate manufacturing process.

The choice of manufacturing process depends on various factors whereasthe surface intended for the machining can be fully exposed.

The method according to FIGS. 1-3 could thus also be used—particularlyif it is a question of providing the whole, or only parts of the surfacearea 41 a with a topographical surface structure.

Methods shown and described in Swedish patent applications No. 9800462-5(corresponding to International patent application PCT/SE 99/00145) andNo. 9800839-4 (corresponding to International patent application PCT/SE99/00146) may also be used. Particularly if the whole or parts of thesurface areas are to be given sensor-sensitive properties and a 3Dstructure.

The invention also reveals the possibility of having a surface extensionand/or surface width on a substrate machined to a desired microstructureand thereafter cutting the substrate so that a cut slice will have achosen surface area delimited from the surface width, where thethickness of the cut slice is adjusted to the desired depth for thecavity 31.

Some currently preferred embodiments in this respect will be describedin the following with reference to FIGS. 5, 6, 7 and 8.

According to the invention, thus, any suitable procedure whatsoever canbe used to manufacture surface areas formed to a microstructure.

A considerably more complicated microstructure can therefore be offered,using simple means, than can be achieved via the X-ray silhouette inposition B of FIG. 1.

The discrete element 41 shall thus be applied on and secured to the baseplate 42, and this can be done using means known per se, not describedin further detail here. Suitable means include a screw joint, pasting orgluing or the like.

It is now obvious that this element 41, with said surface area 41 aformed to a microstructure, secured to the base plate 42 will form amould body 40 and that the use of this mould body 40 to produce a matrixor, alternatively, an object will result in the latter having at leastone surface area 31 a formed to a microstructure, complementary to thesurface area 41 a of said discrete element, as shown and described inconjunction with FIG. 3.

According to the present invention the surface area 41 a of the discreteelement 41, formed to a microstructure, will be particularly suited forconnection via a distinct edge or rim extension 41 a″, to the uppersurface 42′ of the base plate 42.

This therefore guarantees that the whole surface 41 a will betransferred to the matrix or, alternatively, the object 31 as anaccurate complementary surface 31 a.

The embodiment according to FIGS. 1-3, 7 and 8 illustrates that asurface area 41 a formed to a microstructure can be chosen to have a,preferably wall-related, surface area 31 a with 2D structure suited todiffractive optical properties.

According to the invention the surface area 41 a according to FIG. 5 orFIG. 6 may reveal a surface area 41 a′ with 3D structure, preferablywall-related, suited to sensor-active properties, a more complicatedsurface structure than is required for only diffractive propertiesaccording to FIGS. 1-3, for the surface area 21 a.

Since a surface extension and/or surface width can be machined entirelyexposed with known means, they can be provided wholly or partially with2D structure and 3D structure intended to extend over several elements.

The invention now shows according to FIG. 5 that said discrete elementscan be chosen as a slice 44 a, 44 b, 44 c cut from a longitudinallyextending bar or ribbon 44 having an upper surface extension 44 e formedto a unique microstructure and with a surface width 44 f along theentire bar 44.

FIGS. 7 and 8 show that said discrete element 41 can be chosen as a partor a slice cut from a solid of revolution 45, with a surface extensionaround the entire solid of revolution formed to a microstructure.

The bar 44 with the surface extensions 44 e and 44 f formed to amicrostructure can be manufactured in various ways, as describedearlier.

The LiGA process can be used if only diffractive optical properties arerequired. However, a different manufacturing method, such as that shownin the Swedish patent applications mentioned above, is necessary ifsensor-active properties are required as optical properties.

A solid of revolution 45 may be produced by causing a closed, planefigure f to rotate 360 degrees about an axis a, the latter lying both inthe plane of the figure f and also does not intersect the figure inquestion, in accordance with FIG. 7.

FIG. 8 illustrates how a slice 45 a from a solid of revolution 45 may beprovided with a polished outer surface 45 c and that a surface 45 b isturned with a turning tool provided with a diamond, to a diffractivesurface.

According to FIG. 10 the slice 41 is placed in a circular recess 101 ina plate 100, and a transparent plastic material is applied in the emptyspace 102.

The surface 45 b now provides a complementary surface 103 a for anobject 103.

As shown in FIG. 9, this object 103 can now be illuminated from a lightsource 91 with a light comprising several wave lengths.

The light from the light source 91 passes a refractive surface 103 b, isdeflected in this surface towards a diffractive surface 103 a which hasbeen coated with a light-reflecting layer 103 a′, and reflects against anumber of light receivers, two of which have been designated 92 and 93,for wave-length separation.

A diamond-tipped turning tool is provided so that, in combination withthe radial or axial feeding movement of the lathe tool, it can form oneor more circumferential surface extensions on the solid of revolution,some of these producing the surface part 45 b. In this application thesurface extension of the surface area can easily be adapted to revealdiffractive optical properties.

The surface area 45 b, cut from a circumferential surface extension forthe separate discrete element 41, is defined by parallel-related, or atleast substantially parallel-related section surfaces for the solid ofrevolution 45.

The invention in accordance with FIG. 10 is thus also based on a mouldbody composed from a plurality of parts and components, having at leastone surface area, formed to a microstructure, designed so that it can betransferred as a complementary surface area to a matrix or,alternatively, an object.

It is thus clear that the base plate 42 can be applied to a plurality ofdiscrete elements located side by side, with or without surface areasformed to a microstructure, in order to combine discrete elements 41,51, 61 on the base plate 42 to enable complementary surfaces of adifferent structure from that shown for the element 41 to be transferredto the matrix or, alternatively, the object.

Even though the delimiting surfaces for the elements in FIG. 4 have beenshown as having right angles, it is obvious that, within the scope ofthe invention, the elements could have curved or angular delimitingsurfaces.

FIG. 4 can be considered to illustrate that said surface area 41 aformed to a microstructure is provided with one or more surface areasadapted for diffractive optical properties, whereas a surface areaformed to a different surface structure may be provided with one or moresurface areas for sensor-active optical properties.

According to the invention the discrete element 41 of the mould body 40may consist of a cut slice, the thickness -k- of the slice therebydetermining the depth of the cavity. In a sensor application this willin practice be up to 5 mm.

FIG. 11 is intended to illustrate that a plurality of separate pieces ofraw material for discrete elements are retained in a fixture which issecured in known manner to the chuck 111 of a lathe 110.

The lathe should preferably be a precision lathe, such as one providedwith a diamond bit.

It is assumed that the various raw materials are tightly oriented andretained by the fixture 112 so that they will be oriented in radialdirection.

FIG. 11 shows only two of these raw materials 113 and 114, and a lathetool 115.

FIG. 11 illustrates how the lathe tool planes the side surfaces 113 a,114 a of the raw materials 113 and 114 and how the thickness -k- of theelement is produced through corresponding planing of the lateral surface113 b and 114 b.

The surfaces 113 c and 114 c may be turned here in the manner shown inFIG. 8 to form a 2D structure.

Alternatively the planed raw materials 113 and 114 may be removed fromthe fixture 112 and placed close together to form a rod suitable forjoint machining to a number of discrete elements 41, as shown in FIG. 5.

The invention is naturally not limited to the embodiments describedabove and given as examples only, but may undergo modifications withinthe scope of the inventive concept illustrated in the appended claims.

What is claimed is:
 1. A method for manufacturing a mould body servingas an original or master or, alternatively, as a matrix, said mould bodyhaving at least one surface area in the form of a microstructure,designed so that it can be transferred as a complementary surface areato a matrix or, alternatively, an object, characterized in that aplurality of prefabricated discrete elements are produced, that a baseplate belonging to the mould body is applied and secured to at least oneof these discrete elements, that this element is provided with saidsurface area in the form of a microstructure and that a matrix or objectformed by the mould body is provided with a complementarymicrostructured surface area from said discrete element.
 2. A method asclaimed in claim 1, characterized in that the surface area belonging tothe discrete element and formed to a microstructure is adapted to fitonto the base plate by means of a distinct edge or rim extension.
 3. Amethod as claimed in claim 1, characterized in that said surface area inthe form of a microstructure is chosen to entirely or partially reveal asurface area with 2D structure.
 4. A method as claimed in claim 1,characterized in that said surface area in the form of a microstructureis chosen to entirely or partially reveal a surface area with 3Dstructure.
 5. A method as claimed in claim 1, characterized in that saiddiscrete element is chosen as a slice cut from a longitudinallyextending bar with a portion of a surface extension along the bar formedto a microstructure.
 6. A method as claimed in claim 1, characterized inthat said discrete element is chosen as a part of, or a slice cut from asolid of revolution having a portion of a surface extension about thesolid of revolution formed to a microstructure.
 7. A method as claimedin claim 6, characterized in that said solid of revolution is formed bya closed plane figure being caused to rotate 360° about an axis lyingboth in the plane of the figure and situated so that it does notintersect the figure in question.
 8. A method as claimed in claim 6,characterized in that said surface extension in the form of amicrostructure is produced by means of a diamond lathe.
 9. A method asclaimed in claim 6, characterized in that a lathe tool tip provided witha diamond, suitable for diamond turning is shaped so that, incombination with the feeding movement of the lathe tool, it can produceone or more surface extensions on the solid of revolution.
 10. A methodas claimed in claim 9, characterized in that the surface structure of asurface extension is adjusted to reveal diffractive optical propertiesand that said surface area for the discrete element is defined byparallel-related or substantially parallel-related section surfaces forthe solid of revolution.
 11. A method as claimed in claim 1,characterized in that a number of pieces of raw material are secured ina chuck in a lathe and that the machining of these raw blanks produces anumber of discrete elements as finished or semi-finished products.
 12. Amethod as claimed in claim 2, characterized in that said surface area inthe form of a microstructure is chosen to entirely or partially reveal asurface area with 2D structure.
 13. A method as claimed in claim 2,characterized in that said surface area in the form of a microstructureis chosen to entirely or partially reveal a surface area with 3Dstructure.